Ex Parte Chow et al

Patent Trial and Appeal Board

Sep 19, 2013

11015152 (P.T.A.B. Sep. 19, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
11/015,152 12/17/2004 Hungkei Keith Chow 100.2543 6256
46266 7590 09/20/2013
PRIEST & GOLDSTEIN, PLLC
5015 SOUTHPARK DR
SUITE 230
DURHAM, NC 27713
EXAMINER
DOBSON, DANIEL G
ART UNIT PAPER NUMBER
2636
MAIL DATE DELIVERY MODE
09/20/2013 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte HUNGKEI KEITH CHOW,
MANYALIBO JOSEPH MATTHEWS,
DUSAN SUVAKOVIC, and DOUTJE T. VAN VEEN
____________

Appeal 2011-004030
Application 11/015,152
Technology Center 2600
____________

Before CARL W. WHITEHEAD, JR., ERIC S. FRAHM, and
ANDREW J. DILLON, Administrative Patent Judges.

DILLON, Administrative Patent Judge.

DECISION ON APPEAL
Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 21-24. We have jurisdiction under 35 U.S.C.
§ 6(b).
We affirm.
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Application 11/015,152

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STATEMENT OF THE CASE
Appellants describe the invention as follows:
A passive optical network includes an optical line termination
unit (OLT) connected to one or more optical network units
(ONUs) by optical elements. The OLT is capable of
performing downstream transmission to the ONUs at each of a
variety of different bit rates, and each ONU performs upstream
transmission at one or more bit rates. The OLT can sense a bit
rate of a received transmission and change its operation so as to
receive and process the transmission exhibiting the sensed bit
rate. Each of the ONUs receives and processes downstream
transmissions at one or more bit rates, but each ONU is capable
of maintaining a phase and frequency lock to downstream
transmissions at all bit rates supported by the OLT.
Spec. 25, Abstract.
Claim 21 is illustrative, which is reproduced below.
21. A method of data communication comprising:
performing a downstream data transmission from an
optical line termination unit (OLT) to a plurality of optical
network units (ONUs);
as each of the ONUs receives a downstream
transmission, achieving a phase and frequency lock of the
operation of the ONU to a bit rate of the downstream
transmission;
changing the bit rate of the downstream transmission
while it is being received by the ONU;
as the bit rate of the downstream transmission received at
an ONU changes, detecting the bit rate with an ONU bit rate
detection circuit and maintaining a phase and frequency lock at
the ONU to the downstream transmission;
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performing upstream data transmission from the plurality
of ONUs to the OLT at a plurality of bit rates; and
detecting the bit rate of the upstream transmission
utilizing an OLT bit rate detection circuit.
The Examiner relies on the following references as evidence of
unpatentability:
Alb US 6,760,391 B1 July 6, 2004
Shoukei Kobayashi, et al., Multi-Bit Rate Passive Double Star
System Using Time-Unit Packet, Journal of Lightwave
Technology, Vol. 19, No. 2, pp. 150-158 (Feb. 2001)
(hereinafter “Kobayashi”).

REJECTIONS
The Examiner rejected claims 21-23 under 35 U.S.C. § 103(a) as
unpatentable over Kobayashi. Ans., pp. 3-6.1
The Examiner rejected claim 24 under § 103(a) as unpatentable over
Kobayashi and Alb. Id. at pp. 6-7.
The Examiner has withdrawn the rejection of claims 10-16. Id. at p.3.
ANALYSIS
Appellants present each of claims 21-24 as standing or falling with
claim 21 (App. Br., p. 10), which is rejected as obvious over Kobayashi. For

1 Throughout this opinion, we refer to the Examiner’s Supplemental Answer
mailed November 11, 2010 (“Supp. Ans.”), Appeal Brief filed February 17,
2010 (“App. Br.”), Examiner’s Answer mailed May 25, 2010 (“Ans.”), and
Reply Brief filed July 22, 2010 (“Reply Br.”).
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Application 11/015,152

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the reasons below, Appellants have not shown a reversible error in the
rejection of claim 21. See In re Jung, 637 F.3d 1356, 1365 (Fed. Cir. 2011)
(“[T]he Board would not have erred in framing the issue as one of
‘reversible error.’”).
Appellants correctly describe the claimed invention as follows:
Claim 21 addresses a method of data communication
comprising performing a downstream data transmission from an
optical line termination unit (OLT) to a plurality of optical
network units (ONUs). As each of the ONUs receives a
downstream transmission, a phase and frequency lock of the
operation of the ONU to a bit rate of the downstream
transmission is achieved. The bit rate of the downstream
transmission is changed while it is being received by the ONU.
As the bit rate of the downstream transmission received at an
ONU changes, [t]he bit rate is detected with an ONU bit rate
detection circuit and a phase and frequency lock at the ONU to
the downstream transmission is maintained.
App. Br., p. 9. The Examiner does not dispute this description of claim 21’s
scope.
Appellants also correctly describe Kobayashi’s teachings as follows:
Kobayashi teaches a network employing a plurality of
ONUs, each of which may communicate at different bit rates at
different times, and an optical service unit (OSU) adaptable to
each of the bit rates exhibited by the different ONUs in the
network. Each user is assigned a time domain, called a TP, in
the frame, and each user may use any bit rate in his TP within
permitted limits. Each ONU transmits and receives at the same
bit rate and the OSU transmits to an ONU at the same bit rate
employed by the ONU during its transmission. See Kobayashi,
page 150, line 39 – page 151, line 10. The ONUs and the OSU
both employ a bit rate discrimination (BRD) circuit. In the
ONUs, the bit rate discrimination circuit extracts TPs with a
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Application 11/015,152

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known bit rate, while in the OSU, the BRD discriminates
multiple bit rates, requiring that the clock speed of the clock
recovery circuit be changed for each TP. See Kobayashi, page
151, line 30 – page 152, line 2.
App. Br., pp. 7-8. The Examiner does not dispute this description of
Kobayashi’s teachings.
The Appellants and Examiner dispute only whether, as determined by
the Examiner, it would have been obvious for Kobayashi’s ONU’s to decode
data transmissions of changing bitrates in the same manner that the OSU is
disclosed as decoding data transmissions of changing bitrates. Ans., p. 5;
Supp. Ans., pp. 3-4. According to the Examiner, Kobayashi’s ONU’s and
OSU include the same bit rate discrimination (BRD) circuit for detecting
bitrates, thus suggesting that an ONU could be modified so as to – like the
OSU – decode a transmission of changing bit rate in response the BRD
circuit detected bitrate. Id. We hold the Examiner’s proposed modification
is reasonable for the following reasons.
First, each downstream TP has a header that can be used by an ONU
for bitrate discrimination. See e.g., Kobayashi, p. 151, col. 1 (“Each TP,
however, has a different bit rate[.] . . . [The header’s] PR and GT are used
for [BRD].”). Thus, Kobayashi’s data is configured for bitrate
discrimination by an ONU.
Second, as pointed out by the Examiner, the OSU and ONU’s
discriminate bitrates via the same BRD circuit. See Ans., p. 9; Kobayashi, p.
151, col. 2 (“The most characteristic function of the 3R circuit is [BRD].
This circuit is placed in the OSU and ONU.”). And with respect to the
proposed modification, the only notable difference between the OSU and
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ONU’s circuitries is that the OSU regenerates data at changing bitrates by
varying its recovery clock rate in response to the BRD circuit detected bit
rate. See Kobayashi, p. 151, col. 2 – p. 152, col. 1 (“In the ONU, the BRD
circuit has to extract TPs with known bit rate. . . . In the OSU, the BRD
circuit has to discriminate multiple bit rates and this requires that the clock
speed of the clock recovery circuit be changed for each TP. The recovered
clocks are used for data regeneration[.]”); id at Fig. 9. Thus, with
modifications for likewise varying an ONU recovery clock rate, Kobayashi’s
modified ONU would also apparently regenerate data at changing bitrates in
response to the BRD circuit detected bit rate.
In light of the above considerations, the Examiner presented a prima
facie case of obvious for the proposed modification. Appellants have not
presented evidence of an error in an underlying basis of the prima facie case
or evidence of nonobviousness rebutting the prima facie case. See Ex Parte
Frye, 94 USPQ2d 1072, 1075 (BPAI 2010) (precedential) (explaining the
Board’s review of obviousness rejections). Rather, Appellants repeatedly
argue that Kobayashi’s ONU’s and OSU are different, which merely begets
the question of whether it would have been obvious to modify the ONUs in
view of the OSU (i.e., in view of the similarities and differences). For
example, in the Appeal Brief, Appellants argue:
[T]he [OSU] and the ONUs of Kobayashi have different needs
and serve different functions with respect to bit rate selection
and changes. The bit rate selections made by the [OSU] and the
ONUs are performed according to different criteria. As noted
above in the discussion of [withdrawn] claim 10, each ONU is
served by the [OSU], with the ONU selecting its own bit rate
and being served with that bit rate by the [OSU]. The [OSU]
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serves multiple ONUs which may operate at different bit rates
according to criteria set by the users, with different ONUs being
able to exhibit different bit rates and for each ONU to change
its bit rate from TP to TP. Changing downstream bit rates
during transmission to an ONU would not achieve the goals of
Kobayashi, which is to adapt the bit rate provided by the [OSU]
to the bit rate requirements of the ONU as defined by the ONU.
App. Br., pp. 9-10. The argument is not persuasive because it neglects the
proposed modification of the ONUs in view of the OSU. As the Examiner
correctly notes, “the [obviousness] analysis is not limited to the needs and
functions or the goals of the prior art. . . . [And,] a person of ordinary skill
would see that the ONUs (disclosed by Kobayashi) would be improved by
employing the same methods used on the [OSU].” Ans., p. 9.
Despite the Examiner’s urging to address the proposed modification
of the ONU in view of the OSU, Appellants responded by merely
contending again that Kobayashi’s disclosed ONUs and OSU have different
functions, stating:
Examining [Kobayashi’s] Table 1, it is clearly seen that both
the functions and parameters for the receivers of Kobayashi’s
OSU and ONU are listed differently. So, even the relied upon
summary table suggests the receivers are not the same. More
specifically, the OS[U] receiver has a “Gain-Control Amplifier
(GCA)” function and “Dynamic Range & Bit Rate Range” not
listed for the ONU receiver.
Reply Br., p. 2. Similarly, Appellants responded by merely listing
differences between Kobayashi’s ONUs and OSU without any meaningful
explanation of how those differences undermine the proposed modification
of the ONUs in view of the OSU. Particularly, Appellants responded:
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[Kobayashi] states . . . [“]an ONU transmits and receives at the
same bit rate. The OSU, on the other hand, must transmit and
receive at the bit rates of all ONUs.” Kobayashi further states
specifically: “In the ONU, the BRD circuit has to extract TPs
with known bit rates . . . . In the OSU, the BRD circuit has to
discriminate multiple rates and this requires that the clock
speed of the clock recovery circuit be changed for each TP.”
(emphasis added) Further, Kobayashi . . . state[s]: “The OS[U]
BRD circuit uses one high-speed clock to process all bit rates,
whereas the ONU BRD circuit uses its own clock.” Finally, . . .
Kobayashi indicates a prototype for OSU use was built and
tested, but there is no discussion of specifically building an
ONU receiver.
In conclusion, Kobayashi’s ONU clearly does not have
“the same front-end hardware for receiving multiple bit rates
as the [OSU]”.2 As noted above, it does not have the same
hardware because among other reasons its “BRD circuit has to
extract TPs with known bit rates” unlike the BRD circuit of the
OSU which discriminates multiple rates.
Reply Br., pp. 2-3 (citations omitted; footnote and italic emphasis added).
Contrary to the emphasized statements of Appellants’ argument,
Kobayashi’s ONU’s and OSU indeed have the same front-end hardware
insofar as sharing the same BRD circuit for bitrate discrimination. See e.g.,
Kobayashi, Fig. 9. And, given that similarity, the Examiner presented a
reasonable basis for determining that it would have been obvious for
Kobayashi’s ONU’s to regenerate data in the same manner as the OSU; that
is, by varying the recovery clock rate in response to the BRD circuit detected
bit rate. Appellants cannot refute this determination by merely listing
differences between Kobayashi’s disclosed ONU’s and OSU.

2 Quoting the Examiner’s Answer. See Ans., p. 5.
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Application 11/015,152

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In sum, Appellants have not shown a reversible error or presented
rebuttal evidence of nonobviousness.

ORDER
The Examiner’s decision rejecting claims 21-24 is affirmed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).

AFFIRMED

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